This study examined the relationship between teamwork and organisational performance at Mogas Petroleum Company in Kampala, Uganda. Employing a quantitative descriptive correlational design, data were collected from 88 employees using structured questionnaires. Teamwork was operationalised through team communication, team cohesion and trust, team goal alignment, and collaborative decision-making. Organisational performance was measured through operational efficiency, customer satisfaction, and employee retention. Findings revealed significant positive correlations between all teamwork dimensions and organisational performance (r ranging from .612 to .694, p < .001). Multiple regression analysis showed that teamwork dimensions collectively explain 65.9% of the variance in organisational performance (R² = .659, F(4,83) = 40.03, p < .001). Team communication was the strongest predictor (β = .371, p < .001). The study concludes that effective teamwork significantly enhances organisational performance at Mogas Petroleum Company and recommends investment in team communication training, structured team-building activities, cross-functional goal alignment sessions, and participatory decision-making frameworks.